The entire character of the amp is changed. It has more power with the upgraded tubes and more pace and rhythm. Detail is improved and the frequency extremes are dramatically exploded.

The upgraded parts make it quieter, the blacks are blacker which resolves more low-level detail and ambiance.

Soundstaging is improved and imaging more defined, as well as both deeper and wider and with better 3-dimensional layering

The amp is far more dynamic han before, bass has more slam, authority and weight. It goes lower and there is more midbass impact. The bass is no longer flubby "one-note" bass but now sounds more like solid-state in this area

Tonal balance is more even from lows to highs while refining the already amazingly liquid midrange of the stock machine. It now has excellent highs and bass to match the 300B's seductive midband.